Systematic review of the clinical effectiveness and cost-effectiveness of oesophageal Doppler monitoring in critically ill and high-risk surgical patients.

OBJECTIVES: To assess the effectiveness and cost-effectiveness of oesophageal Doppler monitoring (ODM) compared with conventional clinical assessment and other methods of monitoring cardiovascular function. DATA SOURCES: Electronic databases and relevant websites from 1990 to May 2007 were searched. REVIEW
METHODS: This review was based on a systematic review conducted by the US Agency for Healthcare Research and Quality (AHRQ), supplemented by evidence from any additional studies identified. Comparator interventions for effectiveness were standard care, pulmonary artery catheters (PACs), pulse contour analysis monitoring and lithium or thermodilution cardiac monitoring. Data were extracted on mortality, length of stay overall and in critical care, complications and quality of life. The economic assessment evaluated strategies involving ODM compared with standard care, PACs, pulse contour analysis monitoring and lithium or thermodilution cardiac monitoring.
RESULTS: The AHRQ report contained eight RCTs and was judged to be of high quality overall. Four comparisons were reported: ODM plus central venous pressure (CVP) monitoring plus conventional assessment vs CVP monitoring plus conventional assessment during surgery; ODM plus conventional assessment vs CVP monitoring plus conventional assessment during surgery; ODM plus conventional assessment vs conventional assessment during surgery; and ODM plus CVP monitoring plus conventional assessment vs CVP monitoring plus conventional assessment postoperatively. Five studies compared ODM plus CVP monitoring plus conventional assessment with CVP monitoring plus conventional assessment during surgery. There were fewer deaths [Peto odds ratio (OR) 0.13, 95% CI 0.02-0.96], fewer major complications (Peto OR 0.12, 95% CI 0.04-0.31), fewer total complications (fixed-effects OR 0.43, 95% CI 0.26-0.71) and shorter length of stay (pooled estimate not presented, 95% CI -2.21 to -0.57) in the ODM group. The results of the meta-analysis of mortality should be treated with caution owing to the low number of events and low overall number of patients in the combined totals. Three studies compared ODM plus conventional assessment with conventional assessment during surgery. There was no evidence of a difference in mortality (fixed-effects OR 0.81, 95% CI 0.23-2.77). Length of hospital stay was shorter in all three studies in the ODM group. Two studies compared ODM plus CVP monitoring plus conventional assessment vs CVP monitoring plus conventional assessment in critically ill patients. The patient groups were quite different (cardiac surgery and major trauma) and neither study, nor a meta-analysis, showed a statistically significant difference in mortality (fixed-effects OR 0.84, 95% CI 0.41-1.70). Fewer patients in the ODM group experienced complications (OR 0.49, 95% CI 0.30-0.81) and both studies reported a statistically significant shorter median length of hospital stay in that group. No economic evaluations that met the inclusion criteria were identified from the existing literature so a series of balance sheets was constructed. The results show that ODM strategies are likely to be cost-effective.
CONCLUSIONS: More formal economic evaluation would allow better use of the available data. All identified studies were conducted in unconscious patients. However, further research is needed to evaluate new ODM probes that may be tolerated by awake patients. Given the paucity of the existing economic evidence base, any further primary research should include an economic evaluation or should provide data suitable for use in an economic model.